1. Field of the Invention.
The present invention relates generally to the control and management of multiple software sub-systems and, more particularly, relates to a computer program for monitoring changes in values or items in a keyed list propagated by a telemetry stream from a target sub-system.
2. Description of the Relevant Art.
Typically, it is necessary or desirable to monitor certain parameters relating to the operation of a target sub-system. For example, if the target sub-system were a transaction managing sub-system, some parameters of interest would be the number of transactions beginning each second and various threshold values.
In one prior art system, the target sub-system is queried when the value of a relevant parameter is to be monitored. The target sub-system reacts to the query by providing the value of the parameter at the time of the query.
Thus, each time the value is to be monitored the target sub-system must be queried so that the target sub-system provides information to be monitored on demand.
Another known method for monitoring the performance of a target sub-system is to poll the system at regular intervals to request values of parameters.
Both of the above-described methods require that the target sub-system interrupt its current task to provide the information requested. This interruption takes place regardless of whether any changes to the value of the monitored parameter have occurred. Conversely, if an important change takes place between requests the change will not be reported until the next request.
In a transaction managing sub-system, it is important to monitor the system at times of high activity. However, the very act of monitoring decreases the efficiency of the sub-system at a time of high activity.
Further, if the information being monitored is required by different users duplicate requests for the same information may be made.